MATLAB commands
Summary of MATLAB Onramp
Basic syntax
| Example | Description |
|---|---|
x = pi | Create variables with the equal sign (=).The left-side ( x) is the variable name containing the value on the right-side (pi). |
y = sin(-5) | You can provide inputs to a function using parentheses. |
Desktop management
| Function | Example | Description |
|---|---|---|
save | save data.mat | Save your current workspace to a MAT-file. |
load | load data.mat | Load the variables in a MAT-file to the Workspace. |
clear | clear | Clear all variables from the Workspace. |
clc | clc | Clear all text from the Command Window. |
format | format long | Change how numeric output is displayed. |
Array types
| Example | Description |
|---|---|
4 | scalar |
[3 5] | row vector |
[1;3] | column vector |
[3 4 5;6 7 8] | matrix |
Evenly-spaced vectors
| Example | Description |
|---|---|
1:4 | Create a vector from 1 to 4, spaced by 1, using the colon (:) operator. |
1:0.5:4 | Create a vector from 1 to 4, spaced by 0.5. |
linspace(1,10,5) | Create a vector with 5 elements. The values are evenly spaced from 1 to 10. |
Creating matrices
| Example | Description |
|---|---|
rand(2) | Create a square matrix with 2 rows and 2 columns. |
zeros(2,3) | Create a rectangular matrix with 2 rows and 3 columns. |
Indexing
| Example | Description |
|---|---|
A(end,2) | Access the element in the second column of the last row. |
A(2,:) | Access the entire second row |
A(1:3,:) | Access all columns of the first three rows. |
A(2) = 11 | Change the value of the second element an array to 11. |
Array operations
| Example | Description |
|---|---|
[1 1; 1 1]*[2 2;2 2] ans = 4 4 4 4 | Perform matrix multiplication. |
[1 1; 1 1].*[2 2;2 2] ans = 2 2 2 2 | Perform element-wise multiplication. |
Multiple outputs
| Example | Description |
|---|---|
[xrow,xcol] = size(x) | Save the number of rows and columns in x to two different variables. |
[xMax,idx] = max(x) | Calculate the maximum value of x and its corresponding index value. |
Documentation
| Example | Description |
|---|---|
doc randi | Open the documentation page for the randi function. |
Plotting
| Example | Description |
|---|---|
plot(x,y,"ro-","LineWidth",5) | Plot a red (r) dashed (--) line with acircle ( o) marker, with a heavy line width. |
hold on | Add the next line to existing plot. |
hold off | Create a new axes for the next plotted line. |
title("My Title") | Add a label to a plot. |
Using tables
| Example | Description |
|---|---|
data.HeightYards | Extract the variable HeightYards fromthe table data. |
data.HeightMeters = data.HeightYards*0.9144 | Derive a table variable from existing data. |
Logicals
| Example | Description |
|---|---|
[5 10 15] > 12 | Compare a vector to the value 12. |
v1(v1 > 6) | Extract all elements in v1 that are greater than 6. |
x(x==999) = 1 | Replace all values in x that are equal to 999 with the value 1. |
Programming
| Example | Description |
|---|---|
if x > 0.5 y = 3 else y = 4 end | If x is greater than 0.5, set the value of y to 3.Otherwise, set the value of y to 4. |
for c = 1:3 disp(c) end | The loop counter (c) progresses through thevalues 1:3 (1, 2, and 3).The loop body displays each value of c. |
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